Oil burner with rotary combustion chamber



Sept. 25, 1951 w. R. RAY 2,568,763

OIL BURNER WITH ROTARY COMBUSTION CHAMBER Filed NOV. 24, 1947 Zmnentor,

MLL/AM Q PAY Patented Sept. 25, 1951 OIL BURNER WITH ROTARY COMBUSTION CHAMBER William R. Ray, Los Angeles, Calif. Application November24, 1947, Serial No. 787,648

8 Claims. (01. 15877) This invention relates to improvements in burners for fluid fuel, and more particularly to improvements in an oil-burner ofthe rotary-furnace type disclosed in my copending application Serial No. 679,285, filed June 25, 1946. The oilburner of said copending application is characterized by a bowl-like structure in whose interior the combustion is produced; said structure being rotated at high speed so that the flame therein, and that protruding from its mouth, is also rotated; whereby substantially complete combustion of the oil is effected.

It is an object of the present invention to provide, in an oil-burner of the character described, means for still further improving the combustion; this object being achieved by the provision of means for retarding passage of the burning gases from the rotating structure, and, further, by so insulating the structure as to minimize heat losses. I

Another object of the invention is to provide a motorized burner-assembly which includes means for insulating the motor from the heat produced in the rotating combustion-chamber, so that the motor can be arranged close to the chamber to afford a compact assembly.

Another object is to guard against warpage of the rotating structure under the heat of combustion therein.

Another object is to provide a novel driving connection between the motor and the combustion chamber, through separate hollow parts of which connection the fuel-oil and the air are supplied to the chamber.

Another object is to provide, within the combustion chamber, improved means for delivering the fuel-oil as a spray.

For full understanding of the invention, and further appreciation of its features and advantages, reference is to be had to the following detailed description and accompanying drawing, and to the appended claims.

The single figure of the drawing is a sectional view of an oil-burner embodying the present invention.

In the drawing, the numeral I I indicates a hollow bowl-like structure of thin heat-resistant metal. Around the outside of this structure is a jacket I2 which is secured at its top to the structure as by welding; the jacket having a cuplil:e lower extension I3 of reduced diameter. In the space between the jacket and the structure II. is a filling of insulating material I4, such as asbestos, which is confined at the bottom of the structure by a plate I5.

In a central opening through the end or bottom wall I6 of the structure I I, and through plate I5, is a tubular member II which is secured, as

, by welding, at its upper end to the structure and at its bottom to a collar I8 threaded on the hollow shaft I9 of an electric motor generally indicated at 20. The reduced and threaded lower portion of the collar I8 projects through an opening in the bottom wall of the jacket-extension I3, which extension is clamped to the collar by a nut 2 I this nut also serving to attach an air-impeller or vaned blower 22 to the collar. The collar I8 is locked in position on the motor shaft I9 against a stop-nut 23, this nut being secured to the shaft as by solder. A cylindrical member 24, having a tapered upper bore 25 which is plugged at its top, is threaded 0n the portion of the motor shaft projecting above the collar IS, and forms an extension of the shaft. Around the cylindrical member 24 is a tube 26 which fits on and is secured to an enlarged lower portion of the member, so that there is an air space between the tube and the major upper portion of the member.

The tube 26 extends above the member 2 3 and there carries an inverted cup 21 of thin heat-resistant metal and having an outwardly inclined side wall; the cup being held in place by a hollow plug 28 secured to the cup and frictionally engaging the inner surface of the tube; the cap-nut 29 serving as a knob for removing the cup. Projecting laterally, and slightly downwardly, from the upper end of the member 24, through openings in the tube 25, is a plurality of tubes 36 which communicate with the bore 25. Within the cup 2'! is an annular screen 3| whose bottom edge fits around a raised portion of the end wall It of the structure I I.

The electric motor 20 is of conventional construction (except that its shaft I9 is hollow) and the interior parts of the motor therefore will not be described. The motor is mounted at its bot tom, by means of a hollow cylindrical fitting 32, onthe bottom wall 33 of ahousing 34 which includes a cylindrical side wall 35 and a marginal top-wall 36; the housing having supporting legs 31. The fitting 32 is attached to the motor by screws and has a reduced portion extending through an opening in the wall 33 and threaded externally to fit a hollow cap 38 which clamps the rugated metallic bellows 42 is secured at its opposite ends, as by solder, to the bottom of fitting 32 and to a shell 43 sealingly attached to the collar 40. The arrangement described constitutes a fluid-tight rotary seal around the bottom of the hollow motor shaft; it being understood that the interengaging surfaces of the collars 39 'and 40 are suitably-lapped. Communicating with the hollow of the motor shaft, by way of the space between the cap 38 and the lower portion of fitting 32, is a pipe 44 threaded in an opening throug the side wall of the cap.

Secured, as by spot-welding, to the marginal top-wall 35 of the motor housing, and forming an inward extension of the wall, is a shallow cupped member 45 which, together with a cover plate 45, constitutes a casing for the blower 22. A chamber 41, above the blower casing and around the burner-jacket extension I3, is defined by the cover plate 46 and an inverted cupped member 48 (both suitably apertured to fit freely around the extension I 3), the member 48 being secured to the lower cupped member 45 by screws 49 passing through relatively large openings 56 in the cover plate; there being a circumferential row of the openings 50 whereby free passage of air from the blower easing into chamber 41 is permitted. Around the burner structure, and mounted on the top of member 48, is an annular member which carries at its top a combustion ring 52, and also a circular heat-deflecting plate 53.

Secured in a central opening through the member 45 is a fitting 54 which furnishes support for the upper end of the electric motor 26 through the agency of a hollow member 55 whose upper end fits within the bore of the fitting and whose lower end is formed to fit around a circular boss on the motor. The cylindrical lower portion of the stop-nut 23 fits in the upper end of the bore of fitting 54 to furnish additional bearing for the motor shaft. Around the motor is an inverted cup-shaped jacket 56 which is sealingly secured at its bottom to the wall 33 of the motor housing to form a reservoir for lubricating oil, the level of which is indicated by the broken line 51; an opening 58 drilled in the motor permitting communication of the oil with its interior. The top wall of the jacket 55 has a central opening for the dependent flange 59 of the fitting 54, to which it is sealingly secured. Mounted at one end in an opening through the flange 59 is a pipe 60 which is extended to the exterior of the motor housing to maintain the space above the lubricating oil at atmospheric pressure and thereby avoid any tendency for the oil to be drawn upwardly through the fitting 54 under the influence of the blower 22; there also being an opening 6| in the member 55 for the same general purpose.

Around a large opening at the right-hand sidev of the motor housing is an air duct 62 which is provided with a closure 63 for regulating the air supply; there being an adjustable opening 64 in the closure which determines the minimum supply. Secured to the inner wall of the motor housing, above the air-duct opening, is a bafile 65 which extends part-way around the jacket 56 and serves to effect better distribution of the air.

Supply of fuel-oil through the pipe 44 is controlled by a throttling valve 66, and also by a fioat valve 61 whereby (when the apparatus is not in operation) the fuel-oil in the hollow motor-shaft l9 and its extension 24 is maintained at the level indicated by the broken line 68. When the blower 22 is in operation, air is drawn through the duct 62 into the motor housing 34 4 and thence, by way of openings 69 in the member 45, into the mouth 10 of the blower; the air being forced from the blower casing through the openings 50 into the chamber 41, whence it passes through openings 1| and 12 in the jacket extension [3 and the tubular member 11, and through the latter into the cup 21 and then downwardly past the rim or mouth 13 of the same into the interior of the burner structure ll. Secondary air for combustion is supplied around the structure ll through openings 14 in the top wall of member 48. At the lower end of tube 26 there are openings 15 whereby cooling air can circulate around the fuel-supply member 24.

In operation, the burner structure is rotated at high speed (conveniently, 1550 R. P. M. when the diameter of the bowl H is six inches) so that the fuel-oil is drawn up the tapered bore 25 by centrifugal force and discharged through the pipes 30 (and through the screen 3 I, which serves to prevent flash-back when the burner is lighted) against the side wall of the cup 21; the

oil being projected from the rim 13 of the cup toward the side wall of the bowl I l as a tangential spray. The air entering the bowl through the mouth of the cup is rotated at high speed due to the friction between it and the inner surface of the bowl, so that it acts on the oil spray to atomize it and produce a swirling mixture which, when first ignited by any suitable means, burns within the bowl, and also above the mouth of the bowl under high-fire conditions. When the oil is supplied at a low rate, the combustion occurs entirely within the bowl and produces a low-fire as is indicated by the flames 16; an annular bafile or rib 11, formed on the side wall of the bowl, delaying upward passage of the burnin mixture so that it is confined to the bottom region of the bowl and thus permits establishment of a fire of very small size. The rib 11 has utility also under high-fire conditions, since by delaying passage of the burning gases from the lower region of the bowl a high temperature is there produced which results in substantial improvement of the combustion. The inwardly-turned lip 18 of the bowl also serves as a bafile for delaying outward passage of the burning gases, but it has been found in practice that in order to achieve the best results it is necessary to provide a baflle, such as the rib 11, in a lower plane.

As is brought out in the aforementioned c0- pending application Serial No. 679,285, the high efficiency of the burner is due not so much to the intimate mixing of the fuel and air as, rather, to the production of full combustion in the actual interior of the hollow structure II, and, further, to the swirling of the fire within the structure and as it emerges (under high-fire conditions.) from its open end.

By arranging the fuel receiving-and-distributing cup 21 in an inverted position with its mouth close to the end wall It of the structure H, the combustion starts at the bottom of the structure so that the whole of its interior is subjected to the combustion, which results in high internal temperature and improved combustion. Further, the entire outer surface of the cup 21 is normallysubjected to the combustion so that formation of carbon deposits The jacket l2 not only serves to confine the insulating material around the structure H but also to so reinforce the structure as to prevent warpage under the high temperature to which it is subjected; proper balancing of the structure being essential to its high-speed operation.

The compact arrangement shown in the drawing is made possible by the provision of means for protecting the motor from the heat produced in the burner. These means comprise the reservoir of lubricating oil around the motor, the housing around the reservoir and through which the combustion air is drawn, and the blower casing interposed between the burner and the motor assembly.

The specific embodiment of my invention herein shown and described is obviously susceptible of modification without departing from the spirit of the invention, and I intend therefore to be limited only by the scope of the appended claims.

I claim as my invention:

1. A rotary oil-burner, comprising: a hollow structure defining internally a combustion chamber, said structure having an end wall and a side wall generally circular in cross-section, the structure being open at its end opposite the end wall; a cup centrally secured within and to said structure and spaced from the side wall thereof, the mouth of said cup facing said end wall and spaced therefrom; means for supplying fuel-oil to the interior of said cup; means for supplying to said chamber air for combustion of said oil; and a motor for rotating the structure about the axis of its side wall at a speed such that the oil is projected by centrifugal force from the rim of the cup toward the side wall of the structure and is atomized thereby.

2. A rotary oil-burner, as defined in claim 1, wherein said cup is disposed wholly within said structure so that substantially all of the outer surfaces of the cup are exposed to the heat of combustion in said chamber.

3. A rotary oil-burner, as defined in claim 1, and wherein said air supply means includes means to supply primary air for combustion in said chamber by way of the mouth of said cup.

4. A rotary oil-burner, comprising: a hollow structure defining internally a combustion chamber, said structure having an end wall and a side wall generally circular in cross-section, the structure being open at its end opposite the end wall; means for supplying fuel-oil to said chamber; a cup-like member within the chamber for receiving and discharging said oil, said member being carried by said structure and arranged in coaxial and spaced relation to said side wall, the mouth of said member facing in the general direction of said end wall, the discharge rim of the member being in a plane intermediate said end wall and the open end of the structure; means for supplying to the chamber air for combustion of said oil; a motor for rotating said structure about the axis of its side wall at a speed such that the oil is projected by centrifugal force from said rim toward said side wall and is atomized thereby, so that it burns within the chamber when ignited; and baffle means carried by said structure for impeding passage of the burning gases from the chamber.

5. A rotary oil-burner, as defined in claim 4,

and wherein said bafile means comprises means projecting from the inside of the side wall of the structure.

6. A rotary oil-burner, as defined in claim 4, and wherein said baffle means comprises an annular rib projecting from the inside of said side wall in a plane intermediate said oil-discharge rim and the open end of the structure.

7. A rotary oil-burner, comprising: a hollow structure defining internally a combustion chamber, said structure having an end wall and a generally-circular side Wall, the structure being open at its end opposite the end wall; a motor for rotating said structure about the axis of its side wall; means forming a driving connection between said motor and said structure, said connection comprising a tubular member secured in a central opening through said end wall and a hollow shaft centrally disposed within said tubular member and spaced therefrom so as to provide a free passage for air therebetween, the end of said shaft extending within said chamber; a fuel cup within the chamber and carried by said structure, said cup being coaxially arranged with respect to said connection and surrounding said end of the hollow shaft, the rim of said cup being in a plane intermediate said end wall and the open end of the structure; means for supplying fuel-oil through said hollow shaft to the interior of said cup; and means for supplying air through said tubular member to said chamber for combustion of said oil.

8. A rotary oil-burner, comprising; a hollow structure defining internally a combustion chamber, said structure having an end wall and a generally-circular side wall, the structure being open at its end opposite the end wall; means for supplying fuel-oil and air to said chamber for combustion therein; an electric motor for rotating said structure about the axis of its side wall, and located adjacent said end Wall; and means for protecting said motor from the heat produced by combustion in said chamber as well as for lubricating the motor, comprising means forming a jacket around the motor and containing lubricating oil, the wall of said motor being apertured to permit communication of said lubricating oil with the interior of the motor and with its bearings.

WILLIAM R. RAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,326,466 Ray Dec. 30, 1919 1,373,149 Ray Mar. 29, 1921 1,722,504 Morris July 30, 1929 1,784,747 Peckelhoff Dec. 9, 1930 1,911,264 Chadwick et a1. May 30, 1933 1,996,336 Junkers Apr. 2, 1935 2,108,621 Straitz Feb. 15, 1938 2,235,468 Vidalie Mar. 18, 1941 2,249,878 Asbury July 22, 1941 FOREIGN PATENTS Number Country Date 697,598 France Nov. 4, 1930 

